Feed supplements are routinely used in raising livestock to assure that the livestock receive sufficient nutrients in their diet, including protein, vitamins and minerals. Such supplements are often fed either in block form, allowing the livestock to feed on a free-choice basis, or mixed into livestock feed in predetermined proportions. When free-choice feeding blocks are used, the amount of such supplement consumed by livestock can generally be controlled by controlling the hardness and palatability of the block.
Feed supplement blocks typically are molasses-based, the molasses providing palatability to the block, and also providing hardness to the block after it is cured, either through evaporative heating and/or chemical curing. Further background on these techniques is provided in U.S. Pat. No. 4,729,896 (Sawhill). Feed supplement mix often also includes molasses as a sweetener to increase palatability of the resultant feed mixture, to assure the livestock ingest the entire portion of nutritionally supplemented feed fed to them.
Such molasses-based feed supplements typically utilize urea as a protein source. Molasses itself typically has only about 8% protein. Urea is therefore often added to increase the total protein content to, e.g., about 20-24% of the feed supplement. Even at these levels, however, since not all of the urea gets metabolized, the "effective" amount of protein is less than the formulated amount.
In ruminant animals (cattle, goats, sheep, etc.), the urea is processed by the animal's digestive system into needed proteins. Non-ruminant animals (such as pigs, horses, dogs, and young calves), however, do not have the ability to metabolize urea, and the urea can be toxic to them. Thus, free-choice block-type feed supplements must be kept away from non-ruminant animals, which can sometimes be a problem--even if, e.g., horses are kept seperately from cattle, or calves are kept seperately from grown cattle, there is always the danger that the animals will break down fences, etc., obtain access to the feed supplement and consume a toxic quantity before being discovered. If a livestock raiser has a dog, the dog similarly must be kept away from the feed supplement block.
There is a need, therefore, for high-protein feed supplements that do not utilize urea. Although other protein sources are available, such as soybean meal, often they are relatively expensive. Also, there is a desire to have feed supplements that do not rely on sweeteners (such as molasses) to give the product acceptable (even desirable) palatability.